The present invention relates to a high-density, multi-pin connector for mounting a pin grid array (PGA) LSI package or a multi-chip module (MCM) board on a main board.
The recent market trend for multi-pin connectors is as follows.
(1) Mainly developed in the field of multi-pin connectors manufactured by connector makers are those having contact-pin pitches, numbers of pins, etc. which are common to boards generally used.
As for the pitches, for example, 2.54 mm and 1.27 mm are typical.
(2) With the progress of MCM boards, they are increased both in board size (.about..quadrature.100 mm) and in number of pins (about 1000 to 10000 pins), which involve increasing also the size of multi-pin connectors onto which such MCM boards are mounted.
Meanwhile, a multi-pin connector is manufactured by, for example, press-fitting contact pins in a housing, or by integrally molding with contact pins set in a mold beforehand.
An example of a multi-pin connector, which is commercially available, is shown in FIG. 17. In FIG. 17, a plurality of contacts 101 are formed on an upper surface of a base portion 100 on which a PGA LSI package to be mounted, and a plurality of pins 102 for connection to the contacts are formed on a lower surface of the base portion.
The conventional multi-pin connectors mentioned above give rise to some problems which will be described below.
First, the commercially available multi-pin connectors have limitations in contact-pin pitch and number of pins. Mounting for accommodating the high density and narrow pitch is necessary to improve the performance of electronic devices. However, such commercially available connectors cannot sufficiently bring out the performance of electronic devices.
Secondly, in view of the above, there is a way of developing connectors for particular specifications. However, this would not only require substantial time and investment for the development of such connectors, but also may affect the development schedule of electronic devices using the connectors.
Thirdly, when the board size is increased due to the high density and narrow pitch as is in MCM boards, connectors are limited in connector size, number of pins and pitch because of restrictions imposed on the forming pressure, the narrow-pitch structure, the housing size, etc. in a connector housing forming machine.